1. Field of the Invention
The present invention relates to a retrieval apparatus for automatically retrieving an image recorded on a recording medium such as a microfilm, tape, disk, and the like.
2. Related Background Art
In a reader printer and the like, the following retrieval method is known. Marks having a different density from the surrounding portions are respectively printed on a side portion of each image frame in order to retrieve image frames of a microfilm. During film convey, these marks are detected and are counted by a counter. When the count value coincides with a frame number of a desired image, the film is stopped, thereby retrieving a desired image. The retrieved image is projected onto a screen.
Since there are various types of films, a recording position of a mark with respect to an image and a size of the mark is not always the same.
FIG. 5 shows a partial structure of a roll microfilm, and shows four types of microfilms F1 to F4. Referring to FIG. 5, frames 1 recording images are aligned in line on the microfilm F1, and non-transparent frame marks m1 are recorded on the lower side of the respective frames. Each frame mark m1 is printed on each frame so that a distance between the left end (reference end) of the frame 1 and the left end (reference end) of the frame mark m1 becomes .lambda.1.
In the microfilm F2, non-transparent frame mark m2 is recorded on the upper side of each frame 1, so that a distance between the left end of frame 1 and the left end of frame mark m2 becomes .lambda.2.
In the microfilm F3, non-transparent marks m1 and m3 are recorded on the upper and lower sides of the frames 1. The frame marks m1 are provided to each frame, and the case marks m3 are provided to selected frames. The case mark m3 is recorded so that a distance between the left end of the frame 1 and the left end of the case mark m3 becomes .lambda.3. The case mark m3 has a different length in the film convey direction from that of the frame mark m1.
In the microfilm F4, non-transparent marks m1 and m3 are recorded on the upper sides of the frames. The case mark m3 is provided to the start frame of a series of frames which have associated image contents, and the frame mark m1 is provided to other frames. Various other microfilms are also known.
As shown in FIG. 5, the recording position, size, type and the like of the mark are different depending on the types of film. When a retrieval operation is performed using these films, a user must input predetermined retrieval/copy conditions corresponding to a selected film to set the apparatus in a retrieval mode suitable for the type of the film. For example, information corresponding to the mark recording position (distances .lambda.1, .lambda.2, and .lambda.3), information indicating a type of mark information indicating a negative or positive film or a transparent or non-transparent mark, and the like are input through a keyboard or the like to uniform a stop position of an image or to correctly detect a mark. However, the input operation of the retrieval conditions, i.e., the retrieval mode, is cumbersome, and the input operation to an input apparatus is often forgot. If the input operation is erroneously performed or is forgot, the stop position of an image is drifted and an image cannot be projected onto an appropriate position of a screen. When the projected image is to be copied, the image is partially deleted, or the image cannot be accurately retrieved.